Method of producing connector bars



1948. w. R. SCHERER 2,446,490

METHOD OF PRODUCING CONNECTOR BARS Filed June 1, 1944 WRAPPER WRAPPER Patented Aug. 3, 1948 UNITED STATES PATENT OFFICE Wayne R. Scherer, Trooper, Pa., assignor to Taylor Fibre Company, Norristown, Pa., a corporation of Pennsylvania Application June 1, 1944, Serial No. 538,222

3 Claims. 1

This invention relates to an improvement in the method of producing connector bars.

Connector bars are provided in circuit breakers, which find various uses, as, for example, in switch mechanism; and, mounted for rotation, carry contacts for the making and breaking of circuits.

As is well known, contact bars have heretofore been formed from metal, as steel, and of substantial size, since they are subjected to consider- :able torque. The metal bar is covered with an insulating material, as fabric or paper, impregrnated with a synthetic resinous material, as a phenol formaldehyde resin, which is molded to the contour of the bar, which is usually four sided.

The contacts are clamped to the bar outside of the insulating covering, which extends somewhat beyond the end of the bar to enable the ends to be .sealed with insulating material.

Contact bars as heretofore made have been open to various objection in that no means are provided to insure against endwise movement of the metal bar in the insulating covering, beyond the frictional engagement of the covering with the bar; and their production has only been accomplished by separately wrapping the bars.

Now in accordance with this invention from the product standpoint, a contact bar, of the type indicated, is provided of such construction that the metal bar is positively held against endwise movement; while from the method standpoint procedure is provided whereby a plurality of the bars of the novel construction may be wrapped simulaneously with accuracy and dispatch.

Having now indicated, in a general way, the nature and purpose of this invention, I will proceed to a detailed description of a preferred procedure for the production thereof, all with reference to the accompanying drawing in which:

Figure 1 is a side view of a plurality of contact bars assembled for wrapping with insulating material.

Figure 2 is a side view, partly in section, of a bar on completion of the wrapping.

Figure 3 is an end view of the subject of Figure 2.

Figure 4 is a side view, partly in section, after molding of the insulating wrapping to the bar.

Figure 5 is an end View of the subject of Figure 4.

Figure 6 is a side view, partly in section, of completed contact bar.

Figure 7 is a sectional view on line 'l-1, Figure 6.

The contact bar according to this invention, shown in Figures 6 and '7, comprises a metal bar A, of steel or any desired suitable metal, and square in cross-section, though the bar may have any suitable cross section, as, for example, circular, triangular, hexagonal, octagonal, or the like.

The bar A will be of suitable length for mounting in a circuit breaker and to carry the desired contacts (not shown).

Molded to the bar A, or otherwise closely conformed to the faces thereof, is an insulating material B, which may be a paper or fabric impregnated with a synthetic resin having insulating capacity, as, for example, a phenol formaldehyde type resin, and which may be applied by wrapping.

The insulating material, which is continuous, extends substantially beyond the ends of the bar A and is formed with a circular bore e of less diameter than the bar so that it extends inwardly over the ends to engage the end faces of the bar in areas (13, thereby providing abutments for the ends and positively preventing endwise movement of the bar A in the insulating material. The outer surface of the insulating material beyond the ends of bar A forms an extension of the surface of the portion conformed to the bar.

The end portions 1) of the insulating material beyond the ends of the bar A may be plugged with insulating material or a disc of insulating material may be secured within the end portions 1) to prevent leakage of current to the ends of the bar A from a contact carried by the bar.

The method according to this invention, for the production of contact bars of the structure described, will be made apparent by reference to Figures 1-5.

A plurality of approximately square metal bars A, bored and tapped at their ends, as at a, a, are assembled together, as shown in Figure 1, by means of circular rods 0 provided with reduced threaded ends (1, d for engagement in the tapped ends a of the bars A.

The circular rods 0 will be of such a diameter that no portion of the peripheries of the rods at the end portions thereof will extend beyond any portion of the end faces of the bar, but the end faces of the corners of the bar A will extend beyond the peripheries of the rods. If the bar A is circular, the rod c will be of less diameter than the bar.

A plurality of bars A having been assembled together, the assembly is mounted in any suitable mechanism, for rotation as a mandrel, and sheets ofinsulati-ng material B are wound upon the several bars A.

The sheets of insulating material B, as has been The wrapping having been completed, the

wrapped bars A Will appear as shownin-Figures 2 and 3, from an inspection of which it will be noted that the insulating material 1B will-"cohlength and will extend beyond the ends of the bars over the rods 0, being in'contact therewith only along lines Where the diameter of the rods equals the diameters of the ends of the'bars A.

The wrapped assembly is now placed in a mold conforming to the contour of the bars'A'and rods 2c and heat and pressure applied toicompress'and conform'the insulating material B to the'bars A and rods and to set the resin.

As :shown in Figures 4 and 5, thepressure ap- 'plied. in the mold compresses theinsulating material and conforms it to thefaces-of the'bars A and, at thesame time, conforms :it to the circular rods 0. The portions-of the insulating material conformed to the rodscare somewhat less dense" than that conformed to the faces of the bars.

However, such portions provide abutments located diagonally of the ends of thebars and engaging those portions of the ends of the bars extending beyond the periphery of the rods, as

shown at m, Figure 5.

When themolding is completed, the assembly is removed from the mold and finally the several insulated contact bars are unscrewed from the several rods c,'whichare then'ava'ilable for the assembly of further bars to be wrapped.

It will be appreciated that various modifica- -tionsin the'particular' structure and procedure described may-be made without departing from my invention or from the scope of the appended 1 claims.

What I claim and desire to protect by Letters Patent-is:

1. The .method 'of'producing a contact connector bar having an insulating covering over its entire length and having portions in contact with the ends of the bar forming abutments for the end faces of the bar, comprising assembling a rod with each end of the bar ofa diameter such that no portion of the peripheries of the rods at the end portions thereof will extend beyond any portion of the periphery of thebar at the end faces of the bar, but portions of the end faces of the bar will extend beyond the peripheries of the rods, wrapping insulating materialoverthe bar and beyond the ends thereof and over portions of the rods extending from the bar, then subjecting the wrapped assembly to pressure to conform the insulating materialto the entire length of the periphery. of. the bar and tothe bar having a plurality of similar plane longitudinal faces with an insulating covering over its entire length and having portions in contact with portions of the end faces of the bar forming 5 abutments for the end faces of the bar, comprising assembling a rod with each end of the bar of a diameter such that no portion of the periphjeriesfof the'rods at thefendportions thereof will -e'xtend beyond any portion of the end faces of the bar but portions of the end faces of the bar Wi11 extend beyond the peripheries of portions of the -rods extendin-g from the bar, wrapping insulating material over the bar and beyond the 'Yendsthereiif overjportions of the rods extending form to the faces of the bars throughout "their lfif f nflthensu jecting e W p ed assemeiytb tressure to conform the insulating material to the entire length of the bar and to the wrapped portions of the rods and into contact 'with tlfe end faces of the portions of the bar extending from the peripheries of the rods, and thenp removing the rods from the bar so that an opening of thejdiameter of the rod is formed in -each-=portion of the insulating material extending from the end faces of the bar to the ends of the insulating material.

3. The -methodof simultaneously covering a =-plurality ;of' contact connector, bars of square I cross-section" with insulation extending over the ;entire-length of the bars and in engagement with thecornerportions of'the end faces thereof to form abutments for the ends of the bars, comprising assembling-in;axial relation a plurality of --bars-and aplurality of rods-with a rod between adjacent barsandia rod, extending from the outer end ofseach end bar; the diameters of the end .portions of; the rods extending from the bars being; such that'no portion or the peripheries of the rods at theg'end portions-extend beyond any portion of the end; faces of the bars, but theend facesof at least' the corners of th bars extend beyond the peripheries of. the end portions of the rods; then simultaneously wrapping a sheet of insulating m aterial including phenol-formaldehyde resin of greater width than the length of the bars -o n each bar andzportionsof; the rods exte d n hei' 01m, .su Ew h W apped sembly toyheat'and pressure to set the resin and to conform the;insulatingmaterial to the entire lergthof the bars andto the portions of the rods ,into contactwith the-end faces of the bars extending from the peripheries of the portions of the rodsextending fromthe ends of the bars and thereafter removing the rodsfrom the bars so that. an opening of the diameter of the rod is formed in each portion of theinsulatingmaterial extending from the end faces of a bar to the ends of. the insulating material.

WAYNE .R. .SCHERER.

itEFEitENC ES CITED The following references are of record inthe file: of this -patent:

UNITED squirts PATENTS lluniber Name Date masses pans nuns--- Nov.,19.1929 .Franl -May 23,1933 aozas o, Langley. .Dec...2 4,1935 2,350,887 'cio'rr June'6,.1'944 FOREIGN PATENTS Number Country I Date 426,324 Great Britain June 30,1933 

